This study was conducted at the JV farms at Gila Valley. Lettuce ‘Raider’ was seeded, then sprinkler-irrigated to germinate seed on September 27, 2021, on double rows 12 in. apart on beds with 42 in. between bed centers. All other water was supplied by furrow irrigation or rainfall. Treatments were replicated four times in a randomized complete block design. Each replicate plot consisted of 25 ft of bed, which contained two 25 ft rows of lettuce. Plants were thinned Jan 6, 2020 at the 3-4 leaf stage to a 12-inch spacing. Treatment beds were separated by single nontreated beds. Treatments were applied by incorporating in soil before seeding or with a tractor-mounted boom sprayer that delivered 50 gal/acre at 100 psi to flat-fan nozzles spaced 12 in apart.
Month |
Max |
Min |
Avg |
Rain |
September |
102 |
75 |
88 |
0.01 |
October |
88 |
58 |
73 |
0.00 |
November |
84 |
53 |
67 |
0.00 |
December |
71 |
44 |
57 |
0.27 |
Fusarium wilt (caused by Fusarium oxysporum fsp lactucae ) rating was done in the field by observing the typical symptom of lettuce wilt. Confirmation was done by cutting the cross section of roots. Readings for germination was taken o on October 5, 2021 and October 22nd 2021. Disease scoring/rating was done on 10-23-21.
The data in the table illustrate the degree of disease control obtained by application of the various treatments in this trial. Plant vigor was normal and phytotoxicity symptoms were not observed in any treatments in this trial.